Challenges in diagnosing chronic constipation and constipation-predominant IBS

The diagnosis of chronic constipation and constipation-predominant irritable bowel syndrome (IBS-C) is challenging because of the considerable degree of symptom overlap, the difficulty in eliciting important information about bowel habits during the history, and the limitations of various diagnostic tests used to evaluate constipation. This article explores these challenges and reviews the elements of the diagnostic process, including the history, the physical examination, the diagnostic criteria for constipation, IBS-C, and dyssynergic defecation, and the motility studies used to differentiate slow-transit constipation from dyssynergic defecation. It also includes 2 case studies to illustrate the overall diagnostic process. The first case study is presented in segments that coincide with the main elements of the evaluation; the second case study is presented at the close as a diagnostic summary for clinicians.